These were a cludge used to prevent userspace's nvif ioctl from
accessing objects created by the kernel for the same client.

That interface was removed in a previous patch, so these are no
longer useful for anything.
Signed-off-by: Ben Skeggs <bskeggs@nvidia.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240726043828.58966-16-bskeggs@nvidia.com